At a news conference in Tokyo in May that was broadcast live on network TV, more than 300 members of the Japanese news media were shocked when Miyazato told them 2017 would be her final season. She said she was no longer motivated to spend most of each year traveling and competing.

She said that she had no immediate plans following this season, but that she hoped to maintain a connection with golf.

When the American news media asked her about her decision this summer at the United States Women’s Open, Miyazato, 32, just smiled and answered in her gentle way.

Miyazato, who is five feet one inch tall, grew up in a small village in Okinawa. In her 14 years as a pro, she has nine L.P.G.A. wins and 59 top-10 finishes, with career earnings of more than $8.2 million.

She also has 15 victories in Japan, was No. 1 in the women’s world rankings for 11 weeks in 2010, and led the Ladies European Tour’s Order of Merit — earnings — in 2011.

Miyazato at the Portland Classic in Oregon in September. In her 14 years as a pro, she has nine L.P.G.A. wins and 59 top-10 finishes.

Jonathan Ferrey / Getty Images

But while she was the best Japanese woman to play golf since Ayako Okamoto — a member of the World Golf Hall of Fame who won 17 L.P.G.A. tournaments in the 1980s and early ’90s — Miyazato knew she had to test herself against the rest of the world. She arrived in the United States in late 2005 for the L.P.G.A.’s final qualifying tournament.

Miyazato said she had followed Juli Inkster, Karrie Webb and Annika Sorenstam on TV and always wanted to compete with them.

“That really motivated me,” she said.

At that annual qualifying school, the L.P.G.A. had to add several modular offices to accommodate the working press corps for the Japanese news media who followed Miyazato to Florida.

Miyazato won the qualifying tournament by 12 strokes to earn full status on the 2006 L.P.G.A. Tour, which is still the record for the largest margin of victory at the event.

That was the beginning of the pressure that Miyazato dealt with for the next 11 years on the United States-based L.P.G.A. Tour, where tournaments are typically four rounds instead of the three-day events in Japan that allowed her to return home frequently.

“It was a big deal when Ai came over here, won Q-school and qualified for the L.P.G.A. Tour,” said Kim Higgins, a bilingual American who works as a videographer for Japanese television. “It had been a long time since a Japanese player of this caliber had come to the U.S. to play.”

When Miyazato returned to America in 2006 for her rookie season, the Japanese news media also returned with high expectations.

“Everybody thought she would come over here and win right away, but that did not happen,” Higgins said.

Miyazato posted seven top-10 finishes that first year, including a tie for third at the 2006 L.P.G.A. Championship. She recorded nine more top-10s in 2007 and 2008 — finally breaking through to win the Evian in 2009, defeating Sweden’s Sophie Gustafson in a one-hole playoff.

Miyazato was moved to tears while announcing her decision to retire at a news conference in Tokyo in May.

Kyodo News, via Getty Images

She won L.P.G.A. tournaments in France, Thailand and Mexico, and throughout the United States, and reached No. 1 in the world – a feat that Okamoto never achieved.

The young pros back home watched in amazement.

“When she wins golf tournaments abroad, it connects to our confidence in Japan,” said Ayaka Watanabe of Japan, who is No. 113 in the world rankings. “She is my favorite, my hero forever.”

But with success came more demands for Miyazato’s time from the always-present news media.

Initially, her handlers tried to manage Miyazato in a more restricted Japanese style, limiting news media access, but when Miyazato noticed that even top American players made time for such requests, her style became more relaxed and accommodating.

“After every round, every practice round, she had to answer a lot of questions,” Inkster said of Miyazato’s off-course demands.

“I usually just walked off the golf course and went to the locker room, but there was a lot more pressure on her,” she added. “She’s really playing for the nation.”

Higgins, who has covered Miyazato for 12 years, said the attention took a toll because the player is a perfectionist who “wants to play well, be good with media, speak perfect English and be liked by others.”

“She’s always had an awareness of those things when most other players don’t,” Higgins said.

As her struggles mounted, Miyazato turned to the L.P.G.A. teaching professionals Pia Nilsson and Lynn Marriott and their Vision 54 school. Marriott said Miyazato wanted to “reignite her passion and intrinsic motivation for practice and competing.”

Miyazato has struggled in recent years to be competitive in tournaments, and it became apparent to her that she was ready for a change.

“She has come to realize there are more roles in life that can be meaningful,” Nilsson said. “Annika Sorenstam finished her career for those reasons. So did Lorena Ochoa.”

Miyazato celebrating her first win at the 2009 Evian Championship. This year’s appearance in Evian-les-Bains, France, will be her last professional tournament.

Stuart Franklin / Getty Images

In July, Miyazato posted her season-best tie for 13th at the Ladies Scottish Open, and she was optimistic for her final appearance in the Women’s British Open the following week.

But during the Tuesday pro-am at the British Open, as Miyazato played with Ricoh’s president, her father and golf teacher, Masaru Miyazato, collapsed while he was following her around the course. She remained by her father’s side until he was taken to a hospital by ambulance. She followed in a car with her mother.

With her father still in a Scottish hospital, Miyazato decided to play in the tournament, but she did not make the cut.

Now, she is preparing for her final event on the tour.

“We’ve got a lot to thank her for,” said Lydia Ko, a pro golfer from New Zealand who is ranked eighth. “She’s done a lot for golf in Japan and not only in Japan, but in the women’s game, too.”

While Miyazato’s L.P.G.A. tour peers are trying to squeeze in dinners, practice rounds and conversations with her before she leaves the circuit, even former L.P.G.A. colleagues are showing up at tournaments to say goodbye to their friend.

The former tour member Meaghan Francella drove from her home in Westchester County, N.Y., to see her friend while the tour was nearby in New Jersey for the U.S. Women’s Open in July. Francella recalled a time when she was struggling with her driver and received a three-page letter from Miyazato, describing her own struggles and how she had solved her swing issues.

“Most people won’t take the time to do something like that,” said Francella, who now works for the Executive Women’s Golf Association.

By early September, Miyazato had dropped to No. 108 in the world rankings, making her the 14th highest-ranked Japanese player. But even with such rising stars as Harukyo Nomura, a 2017 L.P.G.A. tournament winner who is ranked No. 23 in the world, members of the Japanese news media admit there will be a void when Miyazato leaves.

“There are a lot of young players in Japan who are very good, but she is really going to be missed,” said Reiko Takekawa, a veteran golf writer from Japan. “We write about her every single day, whatever happens — good day, bad day. She understands.”

When asked if she felt more pressure or support from the constant interest in her life on and off the golf course, Miyazato smiled. “A little bit of both, to be honest,” she said.

“I’ve learned that you need to find a joy to do what you do every day, even if it’s just an interview,” she added. “Golf is always up and down like life, and I accept that.”